N-component Bose-Einstein Condensate in an Optical Lattice: Destruction of the Condensate and Quasiparticle Properties

TL;DR

This paper models an N-component Bose-Einstein condensate in an optical lattice, analyzing its phase transitions and quasiparticle properties, with exact solutions in the large N limit and insights into superfluid and Mott insulator phases.

Contribution

It introduces an exactly solvable model for multi-component bosons on a lattice and develops a 1/N expansion to study phase behavior and correlations.

Findings

Existence of a superfluid phase with Mott insulator tendencies at high densities

Development of a 1/N expansion for physical quantities

Exact solution in the large N limit

Abstract

We present a model of N-component hard-core bosons on a lattice. The limit N to infinity can be solved exactly. A saddle point approximation leads to a 1/N expansion and allows the calculation of physical quantities like the density of the condensate, the correlation between the components and the density-density correlation function and the correlation between different components. We find a superfluid phase with a tendency towards a Mott insulator at high densities and finite N.